package com.common.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

/*
 * ===========================================================================
 * Copyright 2007 WEBTRANING Corp. All Rights Reserved.
 * WEBTRANING PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 * ===========================================================================
 * @version 1.0, 2007-8-11
 * @author  Jack Chen 
 * ===========================================================================
 * 
 */

public class CharacterEncodingFilter implements Filter {

	protected static String DEFAULT_ENCODING = "UTF-8";
	
	protected String encoding = null;

	protected FilterConfig filterConfig = null;

	protected boolean ignore = true;

	public void destroy() {
		this.encoding = null;
		this.filterConfig = null;

	}

	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

		if (!ignore || (request.getCharacterEncoding() == null)) {
			 if (this.encoding != null)
			    request.setCharacterEncoding(this.encoding);
			 else
			    request.setCharacterEncoding(DEFAULT_ENCODING);
		}
		chain.doFilter(request, response);
	}

	public void init(FilterConfig filterConfig) throws ServletException {

		this.filterConfig = filterConfig;
		this.encoding = filterConfig.getInitParameter("encoding");
		String value = filterConfig.getInitParameter("ignore");
		if (value == null)
			this.ignore = true;
		else if (value.equalsIgnoreCase("true"))
			this.ignore = true;
		else if (value.equalsIgnoreCase("yes"))
			this.ignore = true;
		else
			this.ignore = false;

	}

}
